For 3G mobile communication systems, the call access control policy put forth in the standard document mainly uses a concentrated call access control algorithm in RNC to allocate channel resources according to the current load of the communication system as well as QoS demands of the calling subscriber. Since the processing and implementation of the concentrated call access control algorithm is in the RNC, which is on a higher level in the mobile network hierarchy, sophisticated signaling support between RNC and UE and between RNC and Node_B in the system is required. Therefore, the algorithm is complex in operation and difficult to implement.